Sewing machine drive



Nov. 23, 1948. ,1. w. MOMBERG 2,454,471

snwme pmcanm mum Filed Dec. 21, 1946 Sheets-Sheet l IN V EN TOR. .lzwzesI17. Mar/26: 7:9

NIZNESS: BY

Jouzczd ATTORNEY NOV. 23, 1948 J, w, MQMBERG 2,454,471

SEWING MACHINE DRIVE Filed Dec. 21, 1946 4 Sheets-Sheet 2 INVENTOR.WITNESS James Ill/10772567? ATT0RNEY Now-'23, 1948. .1. w. MOMBERG2,454,471

sawnm mcnnw muvn Filed Dec. 21, 1946 4 Sheds-Sheet} I a 3 R 7 v JamesNMamba? WITNESS BY ATTORNEY Nov. 23, 1948. J. w. MOMBERG SEWING MACHINEDRIVE 4 Sheets-Sheet 4 Filed Dec. 21, 1946 Patented Nov. 23, 1948 UNITEDSTAT-Es PATENT ornce 2,454,471 SEWING MAomNE DRIVE James W. Momberg,Somervilie; N. J., assignor to The Singer Manufacturing Company, Eliza-.beth, N. J., a. corporation of New Jersey Application December 21,1946, Serial No. 717,791

' 9 Claims, (01. 172-36) This invention relates to electric powertransmitters or unitary electric motor and clutch devices such as thoseused as individual drives for industrial sewing, or similar machines,which require frequent starting and stopping by the operator.

In manufacturing establishments where sewing machines are used, thereare large quantities of lint and other foreign material in the air, andwhen motors of the open type are used the'interillustration, my improvedelectric power transnal parts become covered with lint which acts as aninsulator and prevents the proper cooling of the motor parts.

In most instances, the unitary power trans mitter is located beneath thetable top which carries the sewing machine and its bulk must be reducedto a minimum in order to conserve space and not interfere with the legsof the sewing machine-operator One of the objects of the presentinvention is the provision of a unitary electric motor and clutch havinga construction which excludes from the vital internal parts of the motorlint and other foreign material which may be'contained in thesurrounding atmosphere and in which cooling air is forced directly overthe rotor of the motor. D

A further object of the invention is the provivsion of a motor having anexternal rotor which also acts as the driving element of the clutchandthrough a portion of which cooling air is drawn'for the purpose ofcooling both rotor and also directly cooling the driving clutch face.

A still further object of this invention is the provision of a motorframe and an external rotor which cooperate to form a chamber in whichthe stator is enclosed.

With the above and other objects in view, as

will hereinafter appear, the invention Comprises the devices,combinations and arrangements of parts hereinafter set forth andillustrated in the I mitter comprises a frame or casing'made of twoparts l0 and I l and forming a-hollowcylindrically shaped housing forthe working parts of the motor and clutch; The part II is formed with ahub' 35 and a series of ventilating openings 52, and the cup-shapedcasing part In is formed with ventilating openings 5| and an inwardlyextending centrally arranged tubular portion l3 on which is press fitteda stationary electro-magnetic element or stator I 4 having the usualfour-pole three phase windings l5. I

Carried by the tubular portion 13 are the ball bearings l6 and I! inwhich is journaled a, motorshaft I8 having a knurled portion I9 on itsout- 1 board end. I

The rotary electro-magnetic member of the motor is disposed externallyof the stationary member I 4 and comprises a ring type squirrelcagerotor 20 secured to a die-cast spider 2| having a hub 22 cast upon theknurled portion [9 of the motor shaft l8. The rim 23 of the cup-shapedrotary member extends over an annular inwardly extending lip or flange24 formed on the part Ill of the casing. The clearance is small betweenthe flange 24 and the rim 23 ofthe rotor, and as the rotor is operatingat high speed any lint or other particle of foreign matter will bethrown outwardly by the centrifugal action of the rotor and, therefore,the above construction is, in effect, a motor with its operating partstotally enclosed. In order to cool theoperating parts of the motor, thebase of the rotary electro-magnetic member is formed with a series oflaterally extending fan blades 25 each having a flat seat 26 forreceiving a sheet-metal ring 21 held against each seat by a splitspring-ring 28 which enters a suitable semi-circular groove in theoverhanging ledge 29 of each blade. Secured to one of the faces of themetal ring 21 is a ring shaped clutchfacing 30, made of cork or othersuitable material, and extending from its opposite face is a series ofprojections 31 which are adapted to enter holes 32 formed in some of theblades 25. The function of the projections 3| is to prevent the metalring 21 from turning relative to the rotor. It will be understood thatwhen the motor is operating the fan blades, 25 act to draw air from thecenterof the base of the rotor and force it outwardly over 3 the rotorand through the space 50 between the outer periphery of the rotor andthe casing Ill.

Journaled in and extending through the hub I! of the casing part II isan endwise movable shaft 38 carrying a driving pulley 31 on its outboardend, and a driven clutch element 38 on its inboard end. The drivenclutch element 38 is formed with ventilating openings 39 (Figs. 2 and)and is adapted for engagement with either C the drivihg clutch element80 or a brake 40. The brake 40 is carried by a brake supporting ring 4|,pivoted at diametrically opposite points 42 to ,a member 43, hinged at44 to the casing part II. The member 43 is adjustable about its hinge 44by means of an adjusting screw 45 threaded into 9. lug 46 formed on thecasing Ill. The means for shifting the shaft 36 endwise to cause thedriven formed on and projectin from the base of said rotor, and adriving clutch facing secured to the projecting ends of said blades.

3. A unitary electric motor and clutch drive comprising a hollowcylindrical frame having ventilating openings in the ends thereof, astationary motor member carried by said frame,;a cup-shaped rotarymember disposed within the frame externally of said stationary member,said rotary member cooperating with a, portion of said frame to enclosethe stationary member, fan blades formed on the base of said rotarymember, and a clutch facing secured to said fan blades.

4. A unitary electric motor and clutch drive comprising a hollowcylindrical frame having ventilating openings in the ends thereof, astaelement 38 to engage either the driving clutch element or the brakecomprises a sleeve "having threads 48 which cooperate with complementalgrooves formed in the hub 35. The sleeve 41 is turned by means of alever 48 having a split hub 49 which is clamped about the outboard end.

ofthe sleeve 41, For a more detailed description of the means forimparting an endwise movement to the shaft 36 and the brake mechanismreference may be had to the copending application of Edgar P. Turner,Serial No. 696,828, filed Sept. 13, 1946,- for Electric transmitter.

In the operation of my improved motor cooling .expedient, the rotationof the motor 2| causes the fan blades 25 to act as a center intakecentrifugal fan and to draw cooling air through the openings 52 in thecasi'ngpart II and through the openings 39 in the driven element 38. iThe air drawn through these openings is forced along the opening betweenthe casing part III and From the above description, it will beunderstood that the cooling air drawn through'the electric motor andclutch serves to keep both the clutch mechanism and the motor cool andthat foreign material will not find its way into the internal parts ofthe motor.

Having thus set forth the nature of the invention, what I claim hereinis:

1. In an electric motor drive, a cylindrically shaped casi'nghavingventilating openings in the ends thereof, an inwardly extending tubularsupport formed on one of the ends of the casing, a

stator carried by said tubular support, a shaft journaled in saidsupport and carrying a cupshaped rotor at one end thereof, the sides ofsaid rotor beingspaced from said casing to form an air passageway andextending over said stator and cooperating with a portion of the casingto enclose the internal parts of the motor, and air impelling meansformedron said rotor for drawing air through the openings in the casingand forcing it outwardly through said passageway.

2. In a motor and clutch drive, a casing, a stator carried by saidcasing, a cup-shaped rotor carried by said casing and having its rimportion encircling said stator, a series of fan blade tionary motormember carried by said frame, a cup-shaped rotary member disposed withinthe frame externally of said stationary member, said rotary membercooperating with a. portion of said frame to enclose the stationarymember, laterally projecting fan blades formed on said rotary member aclutch facing secured to the project-, ing ends of said blades, andadriven clutch elecooling air is drawn through the clutchelements andforced across the external walls of the rotary member when the motor isin operation.

5. A unitary electric motor and clutch drive comprising a hollowcylindrical frame having ventilating openings in the ends thereof, aninwardly extending flange and a tubular support carried by one end ofsaid frame, a stator carried by said support, a, cup-shaped rotorcarried by said support and having its sides extending over said statorand its rim portion cooperating with said flange to totally enclosethestator, and means carried by said rotor for circulating cooling airover the outer periphery of the rotor.

-6. A unitary electric motor and clutch drive comprising a, hollowcylindrical frame having ventilating, openings in the ends thereof, aninwardly extending flange and a tubular support carried by one end ofsaid frame, a stator carried by said support, a cup-shaped rotor carriedby said support and having its sides extending over said stator and itsrim portion cooperating with said flange to totally enclose the stator,

projecting fan blades formed on said rotor for circulating air over theperiphery of the rotor, and a driving clutch element secured to saidprojecting blades.

7. A unitary electric motor and clutch drive comprising a hollowcylindrical frame havingv ventilating openings in the ends thereof, aninwardly extending flange and a tubular support carried by one end ofsaid frame, a stator carried by said support, a cup-shaped rotor carriedby said support and having its sides extending over said stator and itsrim portion cooperating with said flange to totally enclose the stator,a driven clutch element and a brake carried by the other end of thecasing-said driven clutch element including a disk shaped member havingventilating openings therethrough, a plurality of fan blades extendinglaterallyfrom the base of said rotor, and a driving clutch elementremovably secured to said blades and adapted to be engaged by saiddriven clutch element.

8. A unitary electric motor and clutch drive comprising a hollowcylindrical casing having ventilating openings in its ends and providedwith an internal flange, clutch mechanism located at one end of thecasing, an electric motor 5 stator located at the other end at thecasing, an impertorate cup-shaped rotor having its sides encircling saidstator and its rim portion extending over said flange to totally enclosethe stator. and a series of fan blades formed on the base of said rotorfor drawing air through the openingsln c'ipe end of the. casing, andthrough the 1 clutch and then forcing the air over the sides of prisinga hollow cylindrical casing having 6 stator, said rotor having adiameter less than the diameter of the casing thereby forming a spacebetween the sides of the rotor and the cylindrical ,casing. and a seriesof fan blades for circulating air through the clutch and through thespace between said rotor and said casing.

JAMES W. MOMBERG.

REFERENCES CITED The following references are of record in the tile ofthis patent:

UNITED STATES PATENTS Number Name Date 1,348,539 Breitenbach Aug. 3,1930 1,652,492 Naul Dec. 13, 1927 1,820,985 McKee Sept. 1, 1931

